Two fiber support with single optical amplifier

Abstract

An optical amplifier for a 4-fiber system having two inputs and outputs is provided that makes use of a single amplifier rather than two separate amplifiers. The optical amplifier node makes use of an interleaver before and after the single amplifier to demultiplex and multiplex even and odd channel signals traveling in opposite directions. The arrangement can also amplify wide channel spaced signals traveling through a plurality of optical fibers. The optical amplifier node can be combined with other like amplifier nodes to provide more complex amplifier solutions at reduced costs due to the need for only half of the typical number of amplifiers. The optical amplifier node can also be combined with, e.g., variable optical attenuators, L/C/S filters, channel add/drop, co- and counter-propagating Raman amplification, and dispersion compensation modules to modify the optical signals as desired.

What is claimed is:  
     
       1. A method of amplifying optical signals, comprising the steps of: 
       routing a first plurality of signals through a first combiner to form a first combined plurality of signals;  
       routing a second plurality of signals through a second combiner to form a second combined plurality of signals;  
       routing said first combined plurality of signals and said second combined plurality of signals through a third combiner to form a further combined signal;  
       routing said further combined signal through an amplifier to generate an amplified signal; and  
       routing said further combined signals through at least one dispersion compensation module.  
     
     
       2. A method of amplifying optical signals, comprising the steps of: 
       routing a first plurality of signals through a first combiner to form a first combined plurality of signals;  
       routing a second plurality of signals through a second combiner to form a second combined plurality of signals;  
       routing said first combined plurality of signals and said second combined plurality of signals through a third combiner to form a further combined signal;  
       routing said further combined signal through an amplifier to generate an amplified signal; and  
       routing said further combined signals through a variable optical attenuator.  
     
     
       3. An optical amplifier node, comprising: 
       a first combiner;  
       a first and second input in communication with said first combiner;  
       a first amplifier in communication with said first combiner;  
       a first de-combiner in communication with said first amplifier;  
       a first and second output in communication with said first de-combiner; and  
       a first variable optical attenuator in communication with one of said first input and said first output.  
     
     
       4. The optical amplifier node of  claim 3 , wherein a second variable optical attenuator is in communication with one of said second input and said output. 
     
     
       5. The optical amplifier node of  claim 3 , further comprising at least one dispersion compensation module in communication with said at least one of first and second outputs. 
     
     
       6. The optical amplifier node of  claim 5 , further comprising at least one channel drop device in communication with one of said first de-combiner and said at least one dispersion compensation module. 
     
     
       7. The optical amplifier node of  claim 5 , further comprising at least one channel add device in communication with one of said first de-combiner and said at least one dispersion compensation module. 
     
     
       8. The optical amplifier node of  claim 5 , further comprising a second combiner in communication with said first and second dispersion compensation modules. 
     
     
       9. The optical amplifier node of  claim 8 , further comprising a second amplifier in communication with said second combiner. 
     
     
       10. The optical amplifier node of  claim 9 , further comprising a second de-combiner in communication with said second amplifier. 
     
     
       11. The optical amplifier node of  claim 10 , further comprising at least one variable optical attenuator in communication with said second de-combiner. 
     
     
       12. The optical amplifier node of  claim 3 , further comprising a second amplifier in communication with an L/C/S splitter and an L/C/S combiner. 
     
     
       13. The optical amplifier node of  claim 3 , further comprising a multiplexor in communication with said first combiner. 
     
     
       14. The optical amplifier node of  claim 13 , further comprising a dispersion compensation module positioned on the communication path between said multiplexor and said first combiner. 
     
     
       15. The optical amplifier node of  claim 13 , further comprising a dispersion compensation module positioned on the communication path between said first combiner and said first amplifier. 
         16 .The optical amplifier node of  claim 13 , wherein said first amplifier is a mid-stage access amplifier having a dispersion compensation module. 
     
     
       17. The optical amplifier node of  claim 3 , further comprising a first demultiplexor in communication with said first de-combiner. 
     
     
       18. The optical amplifier node of  claim 17 , further comprising a dispersion compensation module positioned on the communication path between said first demultiplexor and said first de-combiner. 
     
     
       19. The optical amplifier node of  claim 17 , further comprising a dispersion compensation module positioned on the communication path between said first combiner and said first amplifier. 
     
     
       20. The optical amplifier node of  claim 17 , wherein said first amplifier is a mid-stage access amplifier having a dispersion compensation module. 
     
     
       21. The optical amplifier node of  claim 17 , further comprising a co-propagating Raman amplifier in communication with a plurality of fibers. 
     
     
       22. The optical amplifier node of  claim 17 , further comprising a counter-propagating Raman amplifier in communication with a plurality of fibers.